Climate and Plant Community Controls on Soil Carbon: Generalizing Results from Manipulation and Gradient Studies Across Space, Time and Habitat

摘要：我们研究了气候变化对生态系统的影响以及由此产生的气候反馈效应。架空电暖器被用来为落基山脉的草甸地块取暖，取暖的数量预计将与下个世纪全球变暖的数量相当。监测气候变化对土壤小气候、碳和氮循环、植物生长和开花时间以及物种多样性的影响。加热增加了生长季的长度，改变了开花的时间，增加了氮素循环的速度，导致山艾树以牺牲其他植物为代价而膨胀，并导致土壤碳减少了20%。为了扩大我们对这种影响的了解，我们还在调查位于自然海拔和气候梯度上的草甸地块的生态趋势。来自高温地块和自然气候梯度的综合知识正在提供一幅跨越广泛空间和时间尺度的生态系统-气候相互作用的统一图景。

AbstractHarte9815205We investigate the effects of climate change on ecosystems and the resulting feedback effects on climate. Overhead electric heaters are used to warm Rocky Mountain meadow plots by the amount expected from global warming next century. Effects of climate change on soil microclimate, carbon and nitrogen cycling, plant growth and flowering time, and species diversity are monitored. Heating has increased the length of the growing season, altered the timing of flowering, increased the rate of nitrogen cycling, caused sagebrush to expand at the expense of other plants, and caused a 20% decrease in soil carbon. To extend our knowledge of such effects, we are also investigating ecological trends in meadow plots that lie along a natural elevational and climate gradient. The combined knowledge from heated plots and from the natural climate gradient is providing a unified picture of ecosystem-climate interactions across a wide range of space and time scales.